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Hypericum olympicum

Olympic St. John's-wort · Mount Olympus St. John's Wort

Family HypericaceaeGenus Hypericum

A low mound smothered in yellow star flowers with long stamens, in a rock garden
The whole plantKareljPublic domain

About the plant

What it is and where it grows — not part of any germination protocol.

The plant

Habit
Perennial, ShrubExtension Gardener Plant Toolbox
Habit
subshrubPlants of the World Online
Height
0.5-1.7 ft15-50 cmExtension Gardener Plant Toolbox
Spread
0.5-1 ft15-30 cmExtension Gardener Plant Toolbox
Flower
Gold/YellowExtension Gardener Plant Toolbox
Blooms
SummerExtension Gardener Plant Toolbox
Native range
Albania, Bulgaria, Greece, NW. Balkan Pen., TürkiyeGBIF Backbone Taxonomy
Hardiness zones
5-9Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sunExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), Sand, Shallow RockyExtension Gardener Plant Toolbox
Soil pH
Neutral (6.0-8.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Occasionally DryExtension Gardener Plant Toolbox

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; GBIF Backbone Taxonomy — Global Biodiversity Information Facility.

Worth knowing

  • Grown for centuries for its flowers, which are far larger than those of most St John's worts. It won the RHS Award of Garden Merit in 1930 under a wrong name, H. fragile. Wikipedia: Hypericum olympicum

Two sources report 4 treatments between them. All are shown.

Protocol 1

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around March 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 22, 2024.

  1. Dry storage

    Duration: 1095 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: dark

about 3 years from start to sowing. Then 14 days to germinate.

47% germination in 14 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Hypericum p. 39Public domain
Show the original text
Hypericum (Hyperiaceae). Fresh seeds of H. olympicum had germ. only in 70 GA-3 and were dead after DS 6 m (1st Suppl.). A new sample DS 3 y germ. 70D(47% in 2nd w) and 70L(45% in 2nd w). The results are not consistent.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Hypericum p. 39. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 2

DerivedN. C. Deno, 1998

Difficulty Moderate Rated by us, not by the source.

Start around March 23, 2027 for a May 3 last frost. Too late for spring 2027 — that needed starting on March 22, 2024.

  1. Dry storage

    Duration: 1095 daysTemperature: 70°F 21°C

  2. Sow and cover

    Temperature: 70°F 21°C Light: light

about 3 years from start to sowing. Then 14 days to germinate.

45% germination in 14 days.

Seed Germination Theory and Practice, 2nd Supplement — N. C. Deno, 1998 · 2nd Supplement, Hypericum p. 39Public domain
Show the original text
Hypericum (Hyperiaceae). Fresh seeds of H. olympicum had germ. only in 70 GA-3 and were dead after DS 6 m (1st Suppl.). A new sample DS 3 y germ. 70D(47% in 2nd w) and 70L(45% in 2nd w). The results are not consistent.
Seed Germination Theory and Practice, 2nd Supplement, 2nd Supplement, Hypericum p. 39. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 3

DerivedN. C. Deno, 1996

Difficulty Low Rated by us, not by the source.

Start around March 15, 2027 for a May 3 last frost.

  1. Gibberellic acid soak

  2. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 21 days to germinate.

91% germination in 21 days.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Hypericum p. 49Public domain
Show the original text
Hypericum (Hyperiaceae). H. olympicum germ. 70 GA-3(91% in 3rd w) and none in 70L.70D, or 40-70D. Seeds DS 6 m were dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Hypericum p. 49. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

Protocol 4

DerivedN. C. Deno, 1996

  1. Sow and cover

    Temperature: 70°F 21°C Light: light

No stated waiting before sowing.

0% germination.

Nothing germinated at 70.

Seed Germination Theory and Practice, 1st Supplement — N. C. Deno, 1996 · 1st Supplement, Hypericum p. 49Public domain
Show the original text
Hypericum (Hyperiaceae). H. olympicum germ. 70 GA-3(91% in 3rd w) and none in 70L.70D, or 40-70D. Seeds DS 6 m were dead.
Seed Germination Theory and Practice, 1st Supplement, 1st Supplement, Hypericum p. 49. Quoted exactly. Every value on this card comes from this record; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

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